Sheet-metal pipe



R.'J. NORTHAM. SHEET METAL PIPE.

No. 599,628. Patented Feb. 22, 1898.

sum-five NAM E 8. Em A m UNITED STATES PATENT -OFFICE.

. ROBERT J. NORTHAM, OF LOS ANGELES, CALIFORNIA.

SHEET-M ETAL PIPE.

SPECIFICATION forming part of Letters Patent N 0. 599,628, dated February 22, 1898. Application filed December 19, 1896. Serial No. 616,308. (No model.)

Toall whom it may concern.-

Be it known that I, ROBERT J. NORTHAM, a citizen of the'United States, residing at Los Angeles, county of Los Angeles, State of California, have invented certain new and useful Improvements in Sheet-Metal Pipes, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to improvements in sheet-metal pipes whereby I am enabled to readily introduce between the respective layers of the pipe abinding or preserving material; and my invention consists in certain features of novelty hereinafter described and claimed.

Figure I represents a plan view of a section of sheet metal of sufficient width to form two coils when rolled into pipe shape, showing corrugations running lengthwise and extending over one-half of the strip. Fig. II is a similar View to Fig. I, with the exception that the corrugations run partially around the strip instead of lengthwise of the same. Fig. III represents an end View of the pipe when rolled into shape. Fig. IV is a perspective showing pipe rolled into shape and with the corrugations extending lengthwise of the same. Fig. V is a detail View showing the outer edge of the metal as it would appear when the portion of the pipe with corrugations running partially around the same is rolled up into position.

Referring to the drawings, 1 represents a fiat strip of sheet metal before it has been rolled into pipe shape. 2 represents corrugations extending over substantially one-half of said strip,said corrugations running len gthwise of the strip.

3 represents corrugations running partially around the strip. V In the first instance when the pipe has been rolled into position the ends of the corrugations will appear at the end of the pipe. In the second instance the ends of the corrugations will appear along the outer surface of the pipe where the outer end of the metal is lapped onto the body of the pipe. The smooth portion 1 of the pipe forms the inner coil 4, which is smooth on both its inner and outer faces. After one lap has been formed in the pipe the corrugated portions 2 or 3 form the second lap or coil, thereby affording a series of spaces 5, corresponding to the corrugations, which extend in one instance the full length of the pipe and in the other instance around the pipe, the coils of pipe being secured bywire 6 or by other suitable means. After the pipe has been coiled into position and the coils suitably secured I then subject the pipe to a bath of any desired materialsuch, for instance, as asphaltum for the protection of the pipe, or galvanizing material for the cementing and strengthening of the pipe, or any other bath that I may see fit to use-the corrugations permitting the material of the bath to pass readily between the inner and outer coils of the pipe, the spaces between the corrugations remaining filled with the material of the bath when the pipe has been withdrawn.

In Fig. IV Ihave shown a coupling-ring 7, constructed in the same manner as the body of the pipe; but such ring may be made in this manner or not without altering the spirit of my invention.

I claim as my invention- 1. A sheet-metal pipe comprising an inner smooth layer and an outer corrugated layer formed integral with the inner layer and pro- 'viding spaces between the layers; substantially as. described and for the purpose set forth.

2. A sheet-metal pipe consisting of a sheet having a portion of its surface corrugated longitudinally of the pipe, and the whole coiled to produce an inner smooth layer and an outer corrugated layer and spaces between the layers for filling. material; substantially as described.

ROBERT J. NORTHAM. In presence of CHAS. J. ELLIS, J AS. E. KNIGHT. 

